1. Field of the Invention
The present invention relates to a new and distinct variety of bermudagrass, the variety being principally characterized by a darker green summer color, enhanced fall season and overcast weather color and higher shoot density than known bermudagrass.
2. Description of the New Variety
The variety is a new and distinct cultivar taxonomically identified as Cynodon.times.magennisii that was discovered growing under cultivation as a small inclusion in a `Tifgreen` (unpatented) bermudagrass (Cynodon dactylon.times.C. transvaalenis) putting green (No. 14) at the Gulf Shores Country Club, Gulf Shores, Ala. (located approx. latitude 30'15.00 N and longitude 87.degree.39.00 W). This new and distinct cultivar was noticed as an inclusion during extended periods of wet, overcast weather by expressing a darker green color and higher shoot density compared to the surrounding grass. A 5 cm diameter sample plug was taken from the center of the new and distinct cultivar and designated as `MS-Supreme`. The sample plug was transplanted to a fumigated 1 m.sup.2 field plot along with 23 other ecotypes previously collected and located at the Mississippi Agricultural and Forestry Experiment Station Plant Science Research Farm, Starkville, Miss. The `MS-Supreme` and other plots were mowed, fertilized, and watered to promote growth such that all plots had a uniform and dense turf cover by the fall of 1991. During the time period from 1992 to 1996, the 1 m.sup.2 plot of `MS-Supreme` revealed a dark green summer season color (7.5 GY 5/6, Munsell.COPYRGT. Color Charts) and enhanced dark green fall season color (7.5 GY 4/6, Munsell.COPYRGT. Color Charts), high shoot density, short leaf length (4 to 8 mm) and narrow leaf width (0.4 to 1.0 mm), and extremely prostrate growth habit. `MS-Supreme` has been vegetatively re-propagated using plugs (5 to 10 cm diameter) and sprigs (stolon segments of 3 to 10 cm long) taken from the initial 1 m.sup.2 field plot at the Mississippi Agricultural and Forestry Experiment Station Plant Science Research Farm in Starkville, Miss. or from a secondary 5 m.sup.2 plot at the Mississippi Agricultural and Forestry Experiment Station Plant Science Research Farm initiated in 1996 through sprigging. Other experimental plantings of `MS-Supreme` using plugs have been made at the Mississippi State University Golf Course practice green in Starkville, Miss. (Jun. 1995), the Houston Country Club practice green in Houson, Tex. (May 1996) and Sturgis Sod Farm in Sturgis, Miss. (May 1998). Other experimental plantings of `MS-Supreme` using sprigs have been made at the Tupelo Country Club practice green in Tupelo, Miss. (Jun. 1995), the Burning Tree Country Club practice green in Decatur, Ala. (Jun. 1995), the Deerfield Country Club experimental green in Madison, Miss. (May 1998) and the National Turfgrass Evaluation Program (NTEP) On-Site Bermudagrass test locations (May-July 1998). All experimental plantings of `MS-Supreme` using plugs or sprigs have retained their true-to-type morphology. In 1996, a greenhouse study was conducted that measured the comparative plant morphology of `MS-Supreme`, `Tifgreen`, the putting green cultivar `MS-Supreme` emerged from in Gulf Shores and `Tifdwarf` (unpatented) bermudagrass (C. dactylon.times.C. transvaalensis), the closest known Cynodon cultivar. `MS-Supreme`, `Tifgreen`, and `Tifdwarf` were each planted in six 15-cm diameter pots using representative stolon segments of each genotype and grown under optimum greenhouse conditions. All grasses were clipped daily until they fully covered the pots, then grown unclipped for three weeks and sampled. One stolon segment was randomly sampled from each pot and measured to determine their comparative morphology using the newest visible node, the leaf blade and sheath attached to that node, and the internode found preceding that node. After the initial sampling, pots were again regrown and sampled a second and third time according to the above procedures. All genotypes were sampled a total of three times yielding 18 observations per genotype. `MS-Supreme` leaf blade length was significantly (P=0.05) shorter (10.1 mm) and the width narrower (1.5 mm) than `Tifgreen` (length=39.1 mm and width=1.9 mm( and `Tifdwarf` (length=24.9 mm and width=1.7 mm). The internode length of `MS-Supreme` was significantly shorter (length=10.6 mm) and diameter smaller (0.5 mm) than `Tifgreen` (length=19.9 and diameter=0.7 mm). There was no difference in internode length or diameter between `MS-Supreme` and `Tifdwarf`. Evaluations of the turfgrass quality of experimental putting green plots of `MS-Supreme`, `Tifgreen`, and/or `Tifdwarf` were made at the Mississippi State Univerisity Golf Course, Starkville, Miss.; Tupelo Country Club, Tupelo, Miss.; and Burning Tree Country Club, Decatur, Ala. from 1995 to 1997. All plots were evaluated on a visual rating scale of turfgrass putting green quality of 1 to 9; with 1=poor quality, and 9=excellent quality. At the Mississippi State University Golf Course location, `MS-Supreme` had the highest quality ratings (QR's) at the two mowing heights tested (7.8 QR at 3 and 5 mm mowing heights) compared to `Tifdwarf` (6.1 QR at 3 mm and 6.9 QR at 5 mm) and `Tifgreen` (4.9 QR at 3 mm and 5.3 QR at 5 mm). Evaluations at Tupelo Country Club revealed higher quality ratings for `MS-Supreme` (7.8 QR) compared to `Tifdwarf` (6.5 QR). At Burning Tree Country Club, quality ratings for `MS-Supreme` were highest (7.7 QR) compared to `Tifgreen` (4.5 QR) and `Tifdwarf` (7.0 QR). The higher quality `MS-Supreme` compared to the other grasses is attributed to its dark green summer color and enhanced dark green fall color, ultra-dwarf leaf morphology, and extremely prostrate growth habit. `MS-Supreme`, the new and distinct Cynodon cultivar and `Tifdwarf`, the closest known Cynodon cultivar were characterized using DNA amplification fingerprinting (DAF) analysis using primer 8.6i. The DAF analysis of `Tifdwarf` showed the presence of a DNA band at 370 bps and absence of a bands at 200 bps, whereas; the same analysis of `MS-Supreme` revealed the absence of a DNA band at 370 bps and the presence of a band at 200 bps. This analysis is evidence that the cultivars are different and can be positively identified without relying solely on morphological and performance traits. During out 6+ years of greenhouse and field observations of `MS-Supreme`, seedhead formation has not been observed. Under these same conditions, `Tifgreen` and `Tifdwarf` formed noticeable seedheads. Our evaluation of `MS-Supreme` following repeated asexual greenhouse and field propagation has revealed that this new and distinct cultivar remained stable and distinct in its morphological features and turf performance characteristics.
The most noticeable variations among `MS-Supreme`, `Tifgreen`, and `Tifdwarf` are that the new and distinct claimed cultivar `MS-Supreme`, has a dark green summer color (7.5 GY 5/6, Munsell.COPYRGT. Color Charts) and enhanced fall season and overcast weather color (7.5 GY 4/6, Munsell.COPYRGT.Color Charts) an ultra-dwarf leaf blade length (10.1 mm) and width (1.5 mm), and extremely prostrate growth habit. These features contribute to the high turfgrass putting green quality ratings measured at the 3 experimental putting green test sites. `Tifdwarf`, the closest Cynodon cultivar `MS-Supreme` is well distinguished from `MS-Supreme` in the fall season by its anthocyanin color (purple leaf and stolon cast), which is not present in `MS-Supreme`, and by different DNA amplification profiles using DAF analysis. `Tifgreen`, the genotype from which `MS-Supreme` emerged is well distinguished from `MS-Supreme` by its erect growth habit and large sized leaves and stolons. `MS-Supreme`, the new and distinct claimed cultivar is illustrated in the accompanying photographs in comparison with `Tifgreen` and `Tifdwarf` bermudagrass.